Impact properties of film of linear low density polyethylene has been the subject of various patents in the literature, for example U.S. Pat. Nos. 4,743,649 and 4,957,969. Improvements in impact resistance of linear low density polyethylene has been described to result from blending linear low density polyethylene with impact polystyrene or impact poly(para-methylstyrene). Although the addition of impact polymers can improve impact properties of LLDPE film, the impact polymers, on addition to LLDPE, can reduce the stiffness (modulus) of the resulting film. In the literature, the use of microtalc has been described to act as an antiblocking agent in LLDPE production. However, such use of microtalc as an antiblocking agent has also been reported to result in decrease in impact properties of the resulting LLDPE film.
Various additives to increase impact strength of LLDPE do not have a sustained effect; that is, the initial effect of those impact strength enhancer additives tends to decrease as a function of time. Moreover, the impact strength enhancers tend to reduce stiffness properties of the product.